In a packaging bag for packaging a target object such as a food material, edges of a bent film are sealed with a seal, and the target object is contained in the resulting containing space. When a consumer takes out the target object, he or she peels the seal sealing the opening to open the bag. Such a packaging bag is manufactured as follows: containing space, which is partially opened, is formed by bending a film and then sealing the side edges of the film; a target object is charged into the containing space through the opening; and then the opening is sealed.
Patent Literature 1 discloses a packaging bag which is formed by bending a film, overlapping the side edges of the film by envelope seaming., and forming a seal in the overlapping region, and a manufacturing method thereof. Patent Literature 3 discloses a packaging bag which is formed by bending a film, overlapping the side edges of the film by butt seaming, and forming a seal in the overlapping part, and a manufacturing method thereof.
Some of packaging bags include a easy-peel seal (easy-opening portion) for easy-opening. These packaging bags are formed by bonding together the edges of a film by envelope seaming or butt seaming and then forming a easy-peel seal in the bonded region.
Patent Literature 1 discloses a packaging bag which is formed by bending a film into a tubular shape, overlapping the edges of the film, and forming multiple longitudinal seals having easy-peel properties in the overlapping region.
Patent Literature 2 discloses a packaging bag which is formed by bending a film, overlapping edges of the film by butt seaming, and forming a easy-peel seal in the overlapping region.